Recent years have seen experiments conducted for the purpose of studying the effects of a zero gravity environment or a microgravity environment on organisms in outer space so as to rear organisms such as mice flown on a spacecraft such as space shuttle in outer space. The rearing environment for mice or the like in outer space requires facilities for supplying mice or the like with water or liquid diet (hereinafter referred to as water or the like) in the same manner as in the case of rearing mice or the like on the ground. Examples of common facilities for supplying water or the like to mice or the like on the ground include an automatic liquid supply apparatus using gravity. However, such an automatic liquid supply apparatus using gravity cannot be used in a zero gravity environment.
In light of this, examples of facilities for supplying water or the like to mice or the like in outer space may be considered to include a device for automatically supplying water or the like using a motor-driven syringe pump or the like. However, such a motor-driven device needs a power supply and has a relatively heavy weight and large footprint. Therefore, it is not preferable to install such a motor-driven device in a spacecraft with limited loading weight and loading space. In addition, motor-driven devices may fail. A failure of the motor-driven device requires a repair by an astronaut and involves a time-consuming maintenance and management effort.